1. Field of the Invention
The present invention relates to monitors with multiple video inputs, and more particularly to automatic video input detection/selection circuitry.
2. Description of the Related Art
Today""s monitors provide either a single video input port or dual video input ports. A video input port of a monitor allows for communication between a source (such as a computer system) and the monitor. For a monitor with a single video input port, switching the monitor to a different computer system has required significant user involvement. In particular, a computer user to accomplish such a system change must disconnect the current computer system from the video input port and connect the new computer system to the video input port. Due to the limited work space typically available to a computer user, the current computer system would likely be moved to a different work area and the new computer system would be located and brought into the user""s work space. These manual tasks, which are needed whenever a user desires to switch a single-port monitor to a different computer system, not only may be time intensive, but also may exact undue physical exertion upon a computer user.
Although to a lesser degree, user involvement in video input port selection has even remained for dual-port monitors. For a monitor having dual video input ports, when a user desires the monitor to service a different computer system, it has yet been necessary for the user to manually choose a different video input port. For example, if a user were to switch physical connection of a computer system from on e video input port to another video input port, the monitor would maintain a logical connection with the video input port previously connected to the computer system. Only after the user manually chooses the video input port currently connected to the computer system, such as by pressing a video button, would the monitor switch its logical connection to the video input port currently connected to the computer system.
Briefly, in accordance with the present invention, a monitor having multiple video input ports and connectors is provided with automatic video input detection/selection circuitry. The circuitry may automatically detect when an external source such as a computer system is driving a video input port. The circuitry, for example, may detect whether a video input port is being driven by monitoring a sync signal (vertical or horizontal) for the video input port, A video input detect signal for a video input port may be generated from the sync signal for the video input port. In response to assertion of the e video input detect signal indicating a source is driving a video input port, the circuitry may select the particular video input port. A microcontroller of the circuitry may provide a video input selector signal configured to select the video input port. When a single video input port is driven, used interaction is no longer necessary to select the particular video input port. If multiple video input ports are driven, a user may manually choose a particular video input port by pressing a video selection button.